This invention relates to testing electronic devices, and more particularly, to wireless testing of electronic devices using testers.
Electronic devices such as cellular telephones, portable computers, and other devices often contain wireless circuitry. This wireless circuitry may be used, for example, to support wireless local area networking (WLAN) functionality. In a typical scenario, a wireless electronic device may support IEEE 802.11 wireless networking standards (sometimes referred to as WiFi®).
Wireless test equipment is used to test wireless electronic devices. For example, wireless test equipment is sometimes used to perform WLAN tests.
A tester may, for example, perform packet loopback testing. In packet loopback testing, control messages are transmitted from a tester to a device under test (DUT) in the form of a number of data packets. The control messages instruct the DUT to retransmit received data. The returned packets from the DUT are then captured by the tester. The tester analyzes the returned packets using its built-in analysis capabilities. Test analysis may be performed to extract radio-frequency parametric data such as transmit power and error vector magnitude.
The rate at which a DUT retransmits the received data typically varies as a function of link quality. As a result, the tester does not known in advance what data transmission rate will be used by the DUT. When analyzing returned packets from the DUT, the tester may therefore use an analysis model that is not appropriate for that transmission rate. This can lead to erroneous test results. For example, the values computed for the transmit power and error vector magnitude may be incorrect.
It would therefore be desirable to be able to provide improved techniques for wirelessly testing devices under test.